The Germany government’s Federal Environment Agency has predicted that Germany is on the path to have emissions of at least 816 MtCO­2 in 2020, compared to a target of 750 MtCO2, a deficit of 66 MtCO2. (1) However, Germany would be on track to meet its target if it had prioritised closing coal plants instead of nuclear plants.

One reason for the continuing high level of emissions in Germany is its continuing dependence on coal-fired electricity generation. In 2016 coal was responsible for 40% of electricity generation. Nuclear supplied 13%, gas 12%, wind 12%, biomass 7%, solar 6% and hydro 4%. (2)

Germany’s nuclear capacity has reduced markedly this decade as part of its phase-out policy, from 20.4 GWe in 2010 to 10.8 GW in 2016, with an additional 2.9 GW due to close by 2020.

If Germany had prioritized closing coal plants instead of nuclear plants it would have avoided the emission of 80 MtCO2 by 2020, more than enough to make up the deficit needed to achieve Germany’s emissions target. (3)

The 80 MtCO2 emissions avoidance would be delivered if the nuclear plants were operating in a baseload, rather than load following, mode. Over the last seven years the increasing share of intermittent renewable generation has required coal, and on rare occasions those nuclear reactors still operating to curtail their generation. So would nuclear plant have been able to operate at close to full output to deliver the full emissions saving required? Analysis data from Fraunhofer ISE (6) shows that, for the twelve month period to the end of September 2017 this would be the case. Crucially, the output from coal was almost always higher than the output that would have been produced from the closed nuclear generation, so the closed nuclear plant could have operated at close to full capacity in place of coal.

Since 2010, Germany has increased its renewables capacity from 47.4 GW to 106.1 GW in 2016. Its fossil fuel capacity has also increased from 79.4 GW to 83.0 GW. The capacity of coal-fired generation as part of that fossil fuel total remains high, almost unchanged from 49.7 GW in 2010 to 49.2 GW in 2016. (4)

The additional output from renewables since 2010 has barely compensated for the loss of nuclear generation and growth in electricity output. Coal generation remained virtually unchanged, with lignite and hard coal producing 262.9 TWh in 2010 and 261.5 TWh in 2016. Nuclear generation fell from 140.6 TWh to 84.6 TWh, all renewables increased by 84.0 TWh and total electricity output increased by 15.9TWh. (5)

The impact of nuclear closures will worsen soon after 2020. A further 8GW of nuclear capacity is due to close in 2021 and 2022. Such a rapid loss of baseload capacity is unlikely to be compensated for by renewable generation, leading to further reliance on fossil fuel, particularly coal-fired generation.

Earlier this week the German government annouced a series of measures intended to reduce emissions by a further 78 million tonnes of CO2,in an effort to meet their 2020 target. These included a reduction in emissions from coal plants of only 22 million tonnes of CO2. Industry groups say these measures will harm jobs and the economy and Greens describe them as "a hodge podge of nothingness". (7) Even if the new measures are effective the existing programme of closing nuclear plants instead of coal plants will have resulted in the emission of half a billion tonnes of CO2 by 2020.

The global nuclear industry has proposed the Harmony goal, advocating the decarbonisation of the world’s electricity generation mix by 2050. It is proposed that nuclear generation supply 25% of all electricity demand in 2050, with the remainder coming from other low carbon generation.